摘要：Reaction mechanism of humic acids of different origins with chlorine were studied. Volatile chlorinated substances produced by chlorination of humic acid were identified, and possible formation mechanism of one of these substances, chloropicrin, was investigated. Two kinds of humic acids showed different patterns of formation of chloroform and the other chlorinated substances under various conditions for chlorination. High performance liquid chromatography, Sephadex gel chromatography and infrared spectrophotometry of humic acid and chlorinated one demonstrated that these differences are derived from different functional groups in a molecule of humic acid, and that, in addition, humic acid is decomposed to lower molecular weight substances having molecular weight of about several thousands and higher chloroform formation potential. Volatile chlorinated substances were identified to be chloropicrin and carbon tetrachloride besides chloroform by GC-MS with a computerized data system. Precursors for the chloropicrin formation were amino acids such as alanine, threonine, ornithine, glutamic acid and glycine ; nitro- or nitrosophenols ; nitro- or nitrosoresorcinols ; nitromethane and nitroethane. Chloropicrin was produced by chlorination of humic acid and resorcinol in the presence of nitrite. As for mechanism of chloropicrin formation by chlorination of resorcinol in the presence of nitrite, it was recognized that nitroso-substitution of resorcinol occurred in the presence of nitrite and produces nitrosoresorcinol, which was oxidized to nitroresorcinol with hypochlorite, and finally nitroresorcinol formed chloropicrin by the method of the Rook's reaction of chloroform formation from resorcinol.
关键词：humic acid;chlorination;chloroform formation;chloropicrin formation;chlorinated humic acid;precursor of chloropicrin
